定電位法による硫酸酸性飽和硫酸銅溶液中における銅の陽極不働態化の研究

硫酸銅溶液中における銅の陽極不働態化に関する研究 (第1報)

抄録

Here, the mechanism of the anodic passivation of copper in saturated H2SO4-CuSO4 solution has been studied by the potentiostatic method supplemented by optical microscopic observations and chemical analysis of anode deposits.
The anodic passivation of copper during polarization arises from the deposition of cupric sulphate pentahydrate crystals on the anode surface.
The amount of cupric ions in the passive anode deposits, determined by chemical analysis, is nearly equal to that of cupric ions calculated from the amount of current required for passivation.
The shapes and thicknesses of the passive anode deposits change from one-dimensional, needle-like, thin crystals to two-dimensional, plane, thick crystals, corresponding to a decreasing of the applied potential.
The application of Fleischmann-Thirsk theory of crystal growth to the experimental results are discussed. The theoretical curves are found to be applicable for the explanation of the experimental results.This applicability thus renders it possible to estimate the thickness of the passive cupric sulphate deposits.